Field of the Invention
The invention relates to an overhead-line mast with a bar-shaped and insulated mast head, current-carrying conductors fastened to insulators of the insulated mast head, and a ground conductor disposed on a mast tip of the insulated mast head.
The invention can be used, for example, in three-phase overhead lines, but is also suitable for any other type of current (direct current, single-phase current, polyphase currents other than three-phase current).
An overhead-line mast in the form of a straight bar that is made of steel, for example, is clamped at one end in a foundation and includes an upper part which has an insulated construction (insulated mast head) and supports the phase conductors or, in general, the current-carrying conductors as well as the ground conductor (bar-type mast) on the mast tip. Such a structure has large advantages because of the extremely simple shape, the very small width of right of way and the conductor configuration, which is very well suited for minimizing the electric and magnetic field in the vicinity of the surface of the ground.
In order to realize such an overhead-line concept or mast concept, the ground conductor must be guided from the mast tip to the ground. For reasons of insulation, guiding an overhead ground wire outside the mast in air requires appropriately large spacings from the current-carrying conductors, with the result being that the advantages of the very simple mast concept with the smallest widths of right of way do not come to bear.